Process of softening and strengthening degummed vegetable fibers.



GEORGE D. BURTON, OE BOSTON, MASSACHUSETTS, ASSIGNOR TO THE BURTON COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

PROCESS OF SOFTENING AND STRENGTHENING DEGUMMED VEGETABLE FIBERS.

No Drawing.

To all whom it '))HL I/ concern.

lie it known that I, (inouon D. BURTON, a citizen of the United States, and a. resident of Boston, in the county of Suffolk and State of l\/lassachusetts, have invented a new and useful Improvement in Processes of Softenas set'forth in my United States Letters Patent No. 870,157, dated November 5, 1907, the tensile breaking strength of the degummed fiber after such treatment is increased from ten to twenty-two fold and it is no longer harsh andbrittle, but soft and suitable for spinning. I have discovered that such degummed fibers may be softened and strengthened and caused to again adhereor become bound together without using such saponified vegetable oil as aforesaid by treating them with a solution consisting preferably of about two parts of a triatomic or triacid alcohol, such as glycerin, and one part of an alkaline substance, such as sodium carbonate, although I do not limit my self to these proportions.

In carrying out -my process the fiber is degummed in anywitable manner, such as that set forth in my Letters Patent referred to, in which. sodium carbonate is mentioned as one of the several suitable softening agents that may be employed, and the fiber so degummed is then treated with a solution of a suitable triatomic alcohol, such as glycerin, and an alkaline substance, and finally subjected to roller pressure for the purposes set forth in said Letters Patent.

After the degumming process, the fiber Specification of Letters Patent.

Patented Oct. 12, 191 5.

Application filed July 5, 1913. Serial No. 777,499.

bonate or other suitable alkaline substance is used as a softening agent, for, as will be obvious, after the degumming operation, glycerin, or other suitable triatomic alcohol, may be added to the alkaline degumming solution for the purpose of forming the softening and strengthening solution. If sodium carbonate or other suitable alkaline substance is employed as a softening agent, the fiber may be removed from the degumming tank and, without washing it, placed in another tank containing glycerin, or other suitable triatomic alcohol, in which case the alkaline substance, with which the fiber is impregnated, will form, with the glycerin, or triatomic alcohol, a suitable softening and strengthening solution.

.Thatever softening or degummi'ng solution be used, it will be obvious that after the degumming operation, such solution may be drawn off and the softening and strengthening solution put into the tank. In such case, if sodium carbonate or other suitable alkaline substance be 'used as a softening agent and the fiber be washed with Water after the degumming solution is. drawn off,

and an alkaline substance will latter has been drawn off, glycerin or other suitable triatomic alcohol may be added to the tank, in which case the alkaline substance, with which the fiber is impregnated, will form, with such glycerin or other triatoinic alcohol, a suitable softening and strengthening solution; v

The tank in which the degumming operation is carried out, as well as the tank in which the degummed fiber is treated with the softening and strengthening solution, preferably are of such construction that the fiber is agitated during treatment.-

The fiber may be subjected to roller pressure immediately after degumming and before treatment with the softening and strengthening solution, or it may be treated with the latter solution before it is subjected to roller pressure.

If desired, the fiber may be bleached with any suitable bleaching agent, such as an organic acid having an aflinity for. the vegetable fiber-,for instance, oxalic acid or acetic acid, at any stage of the process.

Inasmuch as the gist of my invention is the softening 'and strengthening of the fiber after degumming, by means ofv the solution hereinbefore named, that is to say, feeding it with some substance for which it-has an affinity to take the place of the natural gum which has been removed so as to prevent it from going to the spinning machinery in astarved condition, as it is called,-I do not wish to limit myself to the process set forth in my prior Letters Patent or any other process, inasmuch .,as the process defined by the appended claims is applicable for softening and strengtheningdegummed vegetable fibers, however prepared.

Glycerin, the formula of which is 0 H (OI-1),, is atriatomic or triacid alcohol and "dissolves an alkaline substance, such as sodium carbonate, forming, as I believe, an alkaline alcoholate-or an alkaline glycerid,

' specifically in the present case, possibly, a

glyceryl salt, such as 7 glyceryl carbonate, or

. perhaps, a complex combination of all three;

J claimsto cover a mechanical mixture as wellc but whether the product obtained-by adding glycerin to a solution of an alkaline substance, such as sodium carbonate,- is, strictly speaking, a chemical combination, and if'so,

Whether stable or unstable, or merely a mechanical' mixture, I regard as immaterial so far as the efi'ect'onthe fiber is concerned; and therefore it will be understood that I use the term solution in the appended as a chemical combination, however loose or unstable sit-ch combination may be, of glycerin and an alkaline substance.

In preparing the softening and strengthening solutionf I prefer to add about two parts of glycerin or other suitable triatomic alcohol and one part of a suitable alkaline substance, such as SOdlIlIIl carbonate, to a 3 sufficient quantity of hot water to dissolve A the same; or I' may add'the alkaline substance to the triatoniicalcohol and then add the hotwater. It will beunderstood that'I do not wish to limit myself-to'the exact proportions above set forth inasmuch as have obtained good results by using other pro portions, for example, substantially equal parts of each substance.

1. As animprovement in the art of softening and strengthening degummed vegetable fibers, the process herein described which consists in treating the degummed fiber with a solution consisting of glycerin and sodium carbonate.

2. As an improvement in the art of softening and strengthening degummed vegetable fibers,the process herein described which consolution consisting of approximately two parts ofglycerin and one part of sodium carbonate.

3. .As an improvement in the art of softening and strengthening degummed vegetable fibers, the process herein described which consists in treating thedegummed fiber with sists in treating the degummed fiber with a glycerin and sodium carbonate dissolved hot water. y y

i 4. Asan improvement in the art of soften ing and strengthening degummed vegetable fibers, the process herein described which consists intreating the degummed fiber with Y approximately two parts of glycerin and one part of sodium carbonate dissolved in .hot water. a v

In testimony whereof, I have hereunto subscribed my name this 3rd day of July,

, GEO. D. BURTON.

, Witnesses: Y

E. B. ToMLINsoN, G120. K. WoonwoR'rH, 

